Symptoms: the disease mainly damages its leaves. The young leaves are more likely to be infected. There will be small white spots on the leaves, which will expand into round spots. In serious cases, it will cause the leaves to wither and yellow, causing the leaves to fall.
Prevention and control: it is necessary to strengthen fertilization and pay attention to drainage to prevent excessive humidity. Reduce the source of infection, eliminate dead branches and diseased branches when pruning in winter, spray Triadimefon and zineb when the disease occurs, or use several chemicals in turn.
Symptoms: this disease also damages the leaves. It usually starts from the leaves below, and then gradually spreads upward. There are many spots. When the disease is serious, it will also cause the leaves to turn yellow quickly and fall down in advance.
Prevention and control: attention should be paid to observation, early removal of diseased branches and leaves, and then centralized burning, which can reduce the source of pathogens.
Symptoms: the female adults and nymphs parasitize in the bud armpit, which will suck the juice in the leaves and branches, cause the branches and leaves to blacken, promote the leaves to fall off, seriously affect the growth and development, and their excreta will also induce coal pollution, thus causing other pests.
Prevention and control: it is necessary to strengthen the inspection to prevent the invasion of disease sources, and reasonably apply fertilizer to ensure the improvement of disease resistance.
